Don't run agentless connectors task on Serverless for now (#206609)

## Summary

This PR makes it so that Agentless Connectors task would not be running
on Serverless environments.

### Checklist

Check the PR satisfies following conditions. 

Reviewers should verify this PR satisfies this list as well.

- [ ] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/src/platform/packages/shared/kbn-i18n/README.md)
- [ ]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [ ] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [ ] If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list](https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [ ] This was checked for breaking HTTP API changes, and any breaking
changes have been approved by the breaking-change committee. The
`release_note:breaking` label should be applied in these situations.
- [ ] [Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed
- [ ] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

x-pack/solutions/search/plugins/search_connectors/kibana.jsonc

@@ -22,6 +22,8 @@
       "taskManager",
       "fleet"
     ],
-    "optionalPlugins": []
+    "optionalPlugins": [
+      "cloud"
+    ]
   }
-}
+}

x-pack/solutions/search/plugins/search_connectors/server/plugin.ts

@@ -38,6 +38,7 @@ export class SearchConnectorsPlugin
   private log: Logger;
   private readonly config: SearchConnectorsConfig;
   private agentlessConnectorDeploymentsSyncService: AgentlessConnectorDeploymentsSyncService;
+  private isServerless: boolean;
 
   constructor(initializerContext: PluginInitializerContext) {
     this.connectors = [];
@@ -46,6 +47,7 @@ export class SearchConnectorsPlugin
     this.agentlessConnectorDeploymentsSyncService = new AgentlessConnectorDeploymentsSyncService(
       this.log
     );
+    this.isServerless = false;
   }
 
   public setup(
@@ -55,6 +57,7 @@ export class SearchConnectorsPlugin
     const http = coreSetup.http;
 
     this.connectors = getConnectorTypes(http.staticAssets);
+    this.isServerless = plugins.cloud && plugins.cloud.isServerlessEnabled;
     const coreStartServices = coreSetup.getStartServices();
 
     // There seems to be no way to check for agentless here
@@ -79,7 +82,11 @@ export class SearchConnectorsPlugin
   }
 
   public start(coreStart: CoreStart, plugins: SearchConnectorsPluginStartDependencies) {
-    if (isAgentlessEnabled()) {
+    if (this.isServerless) {
+      this.log.info(
+        'Serverless is not supported, skipping agentless connectors infrastructure watcher task'
+      );
+    } else if (isAgentlessEnabled()) {
       this.log.info(
         'Agentless is supported, scheduling initial agentless connectors infrastructure watcher task'
       );

x-pack/solutions/search/plugins/search_connectors/server/types.ts

@@ -13,6 +13,7 @@ import {
 } from '@kbn/task-manager-plugin/server';
 import { SavedObjectsServiceSetup, SavedObjectsServiceStart } from '@kbn/core-saved-objects-server';
 import { LicensingPluginStart } from '@kbn/licensing-plugin/server';
+import { CloudSetup } from '@kbn/cloud-plugin/server';
 
 /* eslint-disable @typescript-eslint/no-empty-interface */
 
@@ -32,4 +33,5 @@ export interface SearchConnectorsPluginSetupDependencies {
   fleet: FleetSetupContract;
   taskManager: TaskManagerSetupContract;
   soClient: SavedObjectsServiceSetup;
+  cloud: CloudSetup;
 }

x-pack/solutions/search/plugins/search_connectors/tsconfig.json

@@ -27,5 +27,6 @@
     "@kbn/core-elasticsearch-server",
     "@kbn/licensing-plugin",
     "@kbn/core-saved-objects-server",
+    "@kbn/cloud-plugin",
   ]
 }